WASHINGTON (CNN) --Bush administration officials are working the phones this weekend in a bid to build support for a proposed U.N. resolution that would give Iraq until March 17 to disarm or face war.

"We are doing everything we can to avoid war in Iraq. But if Saddam Hussein does not disarm peacefully, he will be disarmed by force," President Bush said in his weekly radio address Saturday.

The measure faces uncertain prospects in the Security Council, where it needs nine votes and no vetoes to pass. U.S. officials have told council members to be prepared for a vote as soon as Tuesday.

The Bush administration has clear support from only three other members: Britain, Spain and Bulgaria. Permanent members Russia, France and China, any of which could veto the measure, have expressed opposition, as have Germany and Syria. Six members remain uncommitted.

French Foreign Minister Dominique de Villepin planned to leave Paris on Sunday to visit the three undecided African members of the council: Angola, Cameroon and Guinea. Pakistan, Mexico and Chile also remain unwilling to back the proposal.

De Villepin argued that Friday's report from U.N. weapons inspectors showed progress, and that the inspectors should be given more time.

But Bush dismissed pleas for more time, saying inspectors need only "what they have never received: the full cooperation of the Iraqi regime."

"The only acceptable outcome is the outcome already demanded by a unanimous vote of the Security Council: total disarmament," he said in his radio address.

The United States and Britain have massed more than 200,000 troops in the Persian Gulf region in preparation for a possible war.

U.N. evacuates personnel

Also Saturday, the U.N. observer force in the demilitarized zone along the border between Iraq and Kuwait, where much of the buildup is concentrated, ordered almost all of its civilian staff to withdraw to Kuwait City and ratcheted up its alert status to "red."

"We are doing this as a protective measure for their safety," Daljeet Bagga, a spokesman for the observer mission, told CNN.

Witnesses have reported that gaps had been opened in the electrified fence along the border, though some have since been closed. The openings could make access across the border easier in the event of an incursion into Iraq.

U.N. observers told CNN that they saw U.S. military personnel apparently scouting in the demilitarized zone Friday, which could be a violation of U.N. rules.

Protesters take to the streets

Meanwhile, the prospect of war brought thousands of demonstrators to the streets in dozens of cities around the world Saturday. A number of supporters of the U.S. hard line on Iraq also turned out.

A rally in Washington, D.C., drew several prominent actors and writers -- including Alice Walker, author of the novel "The Color Purple" -- who was among those arrested after crossing a police line, a U.S. Secret Service spokesman said.

Actress Janeane Garofalo said the White House has not fully explained to the American people the full cost of such a war.

"I don't think that the administration is being particularly honest with the American people about what this is going to cost in life and in dollars, what the dangers are, retaliatory strikes, once it happens," Garofalo said. "This is not a war that needs to happen immediately, if ever."(Full Story)